Imaging mechanisms may include inkjet devices, electrophotographic devices, dye sublimation devices, and lithographic devices. Each imaging mechanism has a series of subsystems which work together to enable the imaging mechanism to produce visible output on an imaging media. Examples of imaging subsystems, from different types of imaging mechanisms, include media transports, fusers, convective heaters, ink delivery systems, developers, and photoreceptors.
Scientists and engineers try to characterize the behavior of each subsystem in an imaging mechanism in order to properly control and improve its performance. Often, there are many xe2x80x9cnoisexe2x80x9d factors which are related to a given subsystem""s performance. Noise factors are factors which the imaging mechanism does not necessarily have control over. Examples of noise factors might be temperature, humidity, and/or air density. Such noise factors can have a dramatic effect on subsystem performance. At times, it may be practical to have a sensor to monitor a particular noise factor, such as a thermometer tied into an imaging mechanism""s controller. In other situations, the cost or size of a particular sensor can be prohibitive. For example, a densitometer for measuring air density may be too expensive or too large to include in a given imaging mechanism.
Although it can be desirable for an imaging mechanism to know the air density, this factor must often be ignored, or assumed to be a nominal value around which the operation of subsystems sensitive to air density must be acceptable, if not able to be improved or optimized. As an alternate solution to having an air density sensor or ignoring air density altogether, some imaging mechanisms allow an operator to enter air density or altitude (which can be correlated to air density) directly into the imaging mechanism via some user interface. While this solution may be cost effective, it is subject to the availability and accuracy of the input made by the operator.